A. Technical Field
In a process comprising the step of carrying out an addition reaction of an alkylene oxide to an addition-receiving substance in the presence of a resin catalyst, thereby producing the addition reaction product, the present invention relates to a process for preserving the resin catalyst as used for the reaction so as to recycle it after being recovered; and utilization of this preserving process.
B. Background Art
In a production process for an addition reaction product (for example, hydroxyalkyl carboxylates and alkylene glycols) by an addition reaction of an alkylene oxide to an addition-receiving substance (for example, carboxylic acids and water) in the presence of a resin catalyst, it is general that the resin catalyst is used in the reaction and thereafter recovered and recycled for a new reaction in order to reduce production costs.
However, when the resin catalyst as used for the reaction is persevered so as to recycle it after it is recovered, there are problems as follows: the unreacted alkylene oxide remaining in the resin catalyst polymerizes and solidifies during the preservation, so the resin catalyst cannot be preserved well and therefore cannot be recycled.